Striking intensity control providing varying adjustments for different type levers



Feb. 8, 1966 J. w. MEINHERZ ETAL 3,233,714

STRIKING INTENSITY CONTROL PROVIDING VARYING ADJUSTMENTS FOR DIFFERENT TYPE LEVERS Filed Sept. 4, 1962 2 Sheets-Sheet 1 INVENTORS JOACH/M kl. ME/A/f/ERZ HERMAN/V H KOCH BY K49 ATTORNEY J. w. MEINHERZ ETAL 3,233,714 ITY CONTROL PROVIDING VARYING ADJUSTMENTS FOR DIFFERENT TYPE LEVERS Feb. 8, 1966 STRIKING INTENS 2 Sheets-Sheet 2 Filed Sept. 4, 1962 INVENTORS dOACH/M W. MEI/VHE/QZ HERMAN/V fl. KOCH A ORNEY United States Patent 3,233 714 STRIKING INTENSITY UONTROL PROVIDING VARYING ADJUSTMENTS FOR DIFFERENT TYPE LEVERS Joachim Wilhelm Meinherz, Paderborn, and Hermann Harald Koch, Buchenhain, near Baierbrunn, Germany, assignors, by mesne assignments, to Soclete De Mecanographie Japy, Paris, France Filed Sept. 4, 1962, Ser. No. 223,575 Claims priority, application Germany, Sept. 9, 1961,

v A 38,290 3 Claims. (Cl. 197-17) stops for the drive camplates in order to limit the engaging period at the end of the drive motion. These stops will be individually adjusted corresponding to the printing surface of the associated type in its space or distance from the drive camplate in order to obtain an equally intensive print of the different types. Further, the stops can be adjusted as a group. Thereby the striking energy of all type-levers, will be changed this being required, e.g. when making various numbers of printed copies. The adjustment is achieved in steps by a handle near the keyboard of the typewriter. Since the stops are designed uniformly and are adjustable by a common member the striking energy of all type levers is varied about equally.

It results, however, in practice that when making a larger number of copies by means of the known devices the types of the small surface characters, e.g. a full stop, a comma, inverted comma, etc. in many cases pierce through the upper sheets so that holes occur. Due to the high striking energy set a too heavy surface pressure on the top paper sheets occurs with these types. The paper does not withstand these strains and tears. This deficiency can be eliminated by setting the striking adjuster to the next lower setting. This, however, results in an insufficient striking intensity for the large-surface letters,

for example M, N, W, and results in a light printing on the last copy sheets.

It is an object of the invention to provide an adjustability of the striking intensity of type levers such that at each position the characters and letters will be printed equally and without damaging the top-most paper sheets. According to the invention a gear has been designed to vary the striking intensity by using differently formed stops for the different camplates, and depending on the size of the type surface to be printed, the basically adjusted ratio between the striking energy of largeand smalhsized types remains nearly equal over the entire adjusting range. The stop members are intended to limit the engaging period of the camplates with the driving roller. The shapes of said members are designed in correspondence with the printing surface of the types, so.

that at a setting motion of the group control gear the effective striking intensity of small type-printing surfaces modified less than said intensity for large-size printing surfaces. Thereby is avoided an extremely high surface pressure on the paper by the types having a small printing surface when the striking intensity is adjusted to print a large number of copies because the effective surface pressure remains within admissible limits. By means of the invention it is further provided that the variation of the striking pressure per unit of printing surface is equal in percentage for all types.

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Further objects of this invention will become evident from the claims and the following detailed description of a preferred embodiment with reference being had to the drawings in which:

FIGURE 1 is a graphical representation showing the striking energies at various settings for two different size types, in accordance with known devices;

FIGURE 2 is a graphical representation of the striking pressures which result from the striking energies taken from FIGURE 1;

FIGURE 3 is a graphical representation similar to FIGURE 1 but as applied to the presently disclosed device;

FIGURE 4 is a graphical representation similar to FIGURE 2 but correlated, instead, to the energies of FIGURE 3; and,

FIGURE 5 is a side view of a preferred embodiment of a device according to the present invention.

The known arrangements to adjust the striking intensity provide approximately the energy variation shown in FIG. 1. In a basic position 1 the type-lever gears are individually adjusted so that the large-surface type as well as the small-surface type produce an approximately equal print whereby for the first mentioned ones more driving energy is required. Line 10 shows the energy variation for from one to four printed copies, of the striking energy of the type printing the letter In while the line 11 shows the same for the comma. The positions 2, 3, 4 will be achieved as known by adjustment of the group control member of the type-levers drive. It may be gathered from the figure that both types show an equal ascent of the striking energy between two dilferent positions.

FIG. 2 shows for the striking energy shown by the FIG. 1 the corresponding variation of the specific surface pressure D/F (total force divided by surface of the type) on the paper for the large-size and small-size types change during the printing. The line 12 corresponds to the character m and the line 13 to the character of the comma. On the ordinate are indicated the striking energies plotted in FIG. 1 in the adjusting positions 1 to 4 for both types In and comma. The point F and the line 14 mark the maximum admissible surface pressure on the paper. When this pressure is exceeded the paper is pierced. At point P the line 14 is met by the characteristic line 13 of the comma-type. Hence already in the adjusting position 3 the topmost paper sheet will be damaged. The foregoing does not take into account the fact that in typewriters in which the drive cam operates on an intermediate lever, the striking energy actually changes with the changing drive angle between the drive cam and the intermediate lever. Because of the fact that the drive cam operates on an intermediate lever, energy variationis normally large within the range of small drive angles, and relatively decreases with an increasing drive angle. The small-sized. types individually adjusted to a small drive angle therefore deviate in practicefrom the diagram of FIG. 1 and have a somewhat larger increase of energy than the large-sized types which are initially adjusted with a large drive angle. The lines 10, 11 in FIG. 1 would therefore run convergently into the direction of the adjusting positions provided for many copies. The above mentioned damaging effect due to the excessive striking energy of the smaller-size types in these adjusting positions will be further increased by this fact.

These disadvantages may be avoided, if the manually adjustable gear which regulates the striking intensity is designed in such a way that the adjustment effects an equal pressure change rather than equal total force change for the large and small size types. This can be achieved by a suitable design of the limitation members which, with the purpose of regulation, cross the pivotal path of each type-lever drive cam. This can be accomplished by providing respective stop members with differently curved cam-abutment surfaces.

The result is that the increase of striking pressure of small surface types is smaller than that of large-surface types, if regulated from one setting position to the following setting position. In FIG. 3 the line marks the variation of the total striking energy of the type in in the regulating positions 1 to 4 The line 16 indicates the same for the type comma. The entire rise of the striking energy between position it and position 4 corresponds as for the comma-type only to a fraction of the corresponding rise of the m-type. Therefrom results that the comma-type causes not so high a surface pressure in the regulating positions 3 and 4 as is produced in other devices. For the type In as well as for the type comma the striking pressure is changed equally.

As isshown by lines 17 and 18 in FIGURE 4,the surface pressure, D/F, increases for m type and for comma type in equal percentage increments rather than unequally as is the case in the diverging pressure lines 12 and 13 of FIGURE 2. Therefore, in FIGURE 4, the maximum pressure line 14- is not crossed by line 18 for any of thefour settings plotted in FIGURE 4. In this same way, all other of the type symbols are regulated. Often it is sufiicient to use only two different camplates one of which is associated with the types with a larger surface, and the other one with those with a smaller surface. Variation of the pressure between type symbols within each group is permissible so long as line 14 is not crossed by any particular type.

FIG. 5 represents an example of the regulating device according to a preferred embodiment of the invention wherein a stop member is used to definitely limit the engagement period of the drive camplate with the driving roller. A type lever 26 is driven by a driving roller 21 through a drive cam 22, an intermediate lever 23 and a pull bar 24 for one stroke of the type lever as soon as the friction element 25 of the drive cam 22 is engaged with the rough circumferential surface of roller 21. This is achieved by a key-lever 27 pivoting on a stationary shaft 26 with which a key-lever spring urged pawl 28 is associated.

When the finger actuable key 29 is depressed, the lever 27 will push against the camplate 22 and pivot it clockwise whereby cam surface 25 will tangentially engage with roller 21 and be driven clockwise by said roller. Camplate 22-will in turn exert a force in the intermediate lever 23 through the resilient spring 33 and thereby pivot lever 23 clockwise. Camplate 22 ceases to rotate lever 23 when the camplate abuts against the stop-lever, 30a or 3%, which crosses the pivotal path of said camplate. The respective stop-levers, 30a and 30b, are pivotally mounted on pivot pin 32 which is mounted on rail bar 31.

Stop-levers 3M and 30b are adjustably fixed against clock- -w1se rotation by set-screw 36 which abuts against one side of a stop-lever and which is threaded through the rail 31. On the other hand the stop-levers may pivot counter-clockwise against the urging of spring 38. There is one set-screw 36 for each stop-lever and each set-screw serves the purpose of permitting individual adjustment of the stop-levers.

Since the stop-levers cannot rotate clockwise, the camplate 22 is definitely stopped when it abuts one of said stop-levers. Although, camplate 22 comes to a stop, the elements 23, 24, and 20 continue to move under the momentum previously imparted to'them by camplate 22 before it abutted the stop-lever. Therefore, camplate 22 may now return to its original at-rest position under urging of spring 33 while elements 23, 24, and 20 are still moving so as to cause the type-head to strike the paper cylinder 47. It is obvious from FIGURE 5, that after lever 23 has rotated ciockwise a certain amount, the pivot axis of'camplate 22 has moved further away from roller 21 and this results in surface 25 losing contact with roller 21. This is what permits spring 33 to pivot camplate 22 back to its at-rest position slightly after the camplate abuts against the stop-lever. After this has occurred, spring 34 serves to return elements 23, 24, and 20 to their positions as shown in FIGURE 5. If key 29 were to still be depressed when intermediate lever 23 is reset by spring '34, camplate 22 would abut against the spring-biased pawl 28 and thereby be pivoted clockwise into engagement with roller 21, to start another stroke of the same typelever 20.

The striking energy of the type 35 at cylinder '47 depends, i.e., on how long a drive stroke the camplate 22 has, that is, how long the camplate is driven before it abuts the stop-lever. This can be varied individually for each type-lever 20 by adjusting the set-screw 36 which presses against nose 37 on the stop-lever. Spring 38 serves to maintain the stop-lever firmly in position with nose 37 pressed against set-screw 36. Adjustment of screw 36 is easily effected from the front of the machine.

Detent cam 39 is provided for effecting a simultaneous adjustment of a whole group of type-levers 20. Cam 3 9 adjusts the pivotal position of rail 31 about its pivot pin 2e. Since rail 31 carries all the set-screws 36 and all thecorresponding stop-levers 300 or 30b, adjustment of rail 31 efiects a simultaneous adjustment of all stoplevers carried by that rail.

Detent cam 39 has spaced round notches 40 which cooperate with roller 41 pivotally carried by rail 31. Spring 42 is connected to rail 31 and to the fixed pivot pin 43 of cam 39 and serves to urge rail 31 in a clockwise direction. Shaft 26 advantageously serves as a bearing for key levers 27 and also for bar 31.

At a swivelling of the detent cam 39 in clockwise direction through a bar 44 by a handle near the keyboard of the typewriter (not shown on the drawing) the rail 31 pivots also clockwise. Thereby the stop lever 30a, 30b are drawn away from the camplates 22 so that the drive path ofthe camplate 22 wiil be lengthened and the striking intensity increased. Each notch 40 corresponds to a regulating position for the striking intensity.

If all the stop-levers were identical to each other, an adjustment of the rail 31 would merely result in an equal change in the total striking force imparted to each keylever 20. But this is exactly the result which is not desired. In order to provide a difference in the variation of striking force for different key-levers, differently shaped stop-levers are provided. In the presently disclosed embodiment, the total number of key-levers '20 is divided into two groups, small and large area type-symbols. The large area key-levers are each associated with a corresponding stop-lever 30a while the small area keylevers are associated with stop-levers 30b. The difierence between these two groups of levers is that the'large area group, 36a, has a concave edge 45 which crosses the path of camplate 22, while the small area group, 30b, has a convex edge 46 which also crosses the path of camplate 22. This difference in edge configuration provides a difference in the extent to which the stroke of each camplate is varied although all the stop-levers may be'equally adjusted. Specifically, an equal adjustment of stop-levers 30a and 301) results in a relatively large change in the length of the driving stroke of those camplates associated with levers 30a as compared to those camplates which are associated with levers 30b, This is graphically plotted in FIGURE 3 with reference to lines 15 and 16.

While we have described above the principles of our invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of our invention as set forth in the objects thereof and in the accompanying claims.

What we claim is:

1. In a typewriter, the combination of a continuously rotating driving roller; an intermediate type-bar conrolling lever; a symbol-carrying type-bar and link means linking one end of said lever to one end of said type-bar; a camplate pivotally mounted on said lever for pivoting motion in a plane perpendicular to the axis of said roller and having a curved portion for tangentially engaging said roller, said roller pivotally driving said camplate when tangentially engaged thereby; means for pivotally driving said lever from said camplate, said driving means comprising a resiliently yieldable element interconnecting said camplate to said lever whereby pivotal movement of said camplate is transmitted through said yieldable element to said lever; means for pivoting said camplate to engage said roller; a rail pivotally mounted in parallel relationship to said driving roller; means for stepwisely securing said rail in various angular positions; an elongate stop-lever pivotally mounted on said rail and extending substantially radially therefrom in said perpendicular plane, said stop-lever having a curved stopping edge portion spaced at a distance from said camplate and crossing the pivotal path of said camplate, said roller rotating in a direction whereby it pivotally drives said camplate, when engaged thereby, along an arc towards said edge portion, said edge portion providing an abutment-stop surface adapted to stoppingly abut against said camplate after said camplate has been pivotally driven by said roller through said distance.

2. The typewriter of claim 1, comprising a first and second group of symbol-carrying type-bars, said first group carrying type-symbols of smaller surface area relative to said second. group of type-bars, each type-bar being drivingly associated with one lever in a corresponding first or second group of said intermediate levers and with one camplate in a corresponding first or second group of said camplates, each said camplate being associated with one stop-lever in a corresponding first or second group of stop-levers, said curved, edge portion for each of said first group of bars being convex towards the associated camplates and said curved edge portion for each of said second group of bars being concave towards the associated camplates, whereby an equal pivotal movement of all said stop-levers provide a lesser effective change in the distances between the first group of stop-levers and. their associated camplates than is provided between the second group of stop-levers and their associated camplates.

3. In a typewriter of the type disclosed, the combination of a continuously rotating driving roller, an intermediate type-bar control lever pivotably mounted about a fixed pivot axis, a camplate pivotably mounted on said lever about a pivot axis which is fixed relative to said lever, said camplate being pivotable from a position of disengagement relative to said roller to a position of tangential engagement with said roller, finger actuable key means for pivoting said camplate into said engagement position, a rail pivotably mounted about a fixed pivot axis, adjusting means for adjustably securing said rail in any one of various pivot positions relative to its pivot axis, a stop-lever pivotably mounted on said rail and extending therefrom perpendicularly to the pivot axis of said rail, abutment means on said rail for preventing pivotal movement of said stop-lever relative to said rail in one pivotal direction, said stop-lever being pivotable in an opposite pivotal direction against the force of a resiliently yieldable means, said stop-lever comprising a curved edge which crosses the pivotal path of said camplate, said camplate being pivotably driven by said roller when engaged therewith and being stopped by abutment of said camplate against said. curved edge, adjustment of said rail to each of said pivot positions causing a different portion of said curved edge to lie in the pivotal path, of said camplate, each said difierent portion of said edge representing a different pivotal position at which said camplate abuts said edge and is stopped thereby.

References Cited by the Examiner UNITED STATES PATENTS 1,173,321 2/1916 Steiner 197--l7 1,818,200 8/1931 Dorsey 19717 2,095,068 10/1937 Koca 19717 2,525,278 10/1950 Yeager 19717 2,734,613 2/1956 Kennedy et al 197--17 2,796,966 6/1957 Toeppen 19717 2,891,650 6/1959 Ascoli 197--17 ROBERT E. PULFREY, Primary Examiner. 

1. IN A TYPEWRITER, THE COMBINATION OF A CONTINUOUSLY ROTATING DRIVING ROLLER; AN INTERMEDIATE TYPE-BAR CONTROLLING LEVER; A SYMBOL-CARRYING TYPE-BAR AND LINK MEANS LINKING ONE END OF SAID LEVER TO ONE END OF SAID TYPE-BAR; A CAMPLATE PIVOTALLY MOUNTED ON SAID LEVER FOR PIVOTING MOTION IN A PLANE PERPENDICULAR TO THE AXIS OF SAID ROLLER AND HAVING A CURVED PORTION FOR TANGENTIALLY ENGAGING SAID ROLLER, SAID ROLLER PIVOTALLY FOR TANGENTIALLY ENGAGING WHEN TANGENTIALLY ENGAGED THEREBY; MEANS FOR PIVOTALLY DRIVING SAID LEVER FROM SAID CAMPLATE, SAID DRIVING MEANS COMPRISING A RESILIENTLY YIELDABLE ELEMENT INTERCONNECTING SAID CAMPLATE TO SAID LEVER WHEREBY PIVOTAL MOVEMENT OF SAID CAMPLATE IS TRANSMITTED THROUGH SAID YIELDABLE ELEMENT TO SAID LEVER; MEANS FOR PIVOTING SAID CAMPLATE TO ENGAGE SAID ROLLER; A RAIL PIVOTALLY MOUNTED IN PARALLEL RELATIONSHIP TO SAID DRIVING ROLLER; MEANS FOR STEPWISELY SECURING SAID RAIL IN VARIOUS ANGULAR POSITIONS; AN ELONGATE STOP-LEVER PIVOTALLY MOUNTED ON SAID RAIL AND EXTENDING SUBSTANTIALLY RADIALLY THEREFROM IN SAID PERPENDICULAR PLANE, SAID STOP-LEVER HAVING A CURVED STOPPING EDGE PORTION SPACED AT A DISTANCE FROM SAID CAMPLATE AND CROSSING THE PIVOTAL PATH OF SAID CAMPLATE, SAID ROLLER ROTATING IN A DIRECTION WHEREBY IT PIVOTALLY DRIVES SAID CAMPLATE, WHEN ENGAGED THEREBY, ALONG AN ARC TOWARDS SAID EDGE PORTION, SAID EDGE PORTION PROVIDING AN ABUTMENT-STOP SURFACE ADAPTED TO STOPPINGLY ABUT AGAINST SAID CAMPLATE AFTER SAID CAMPLATE HAS BEEN PIVOTALLY DRIVEN BY SAID ROLLER THROUGH SAID DISTANCE. 